Yeah, the presale was evil... $30 more than the normal per-head for lawn seats, and they opened it up a few minutes early so my 9am everything was gone. I had a friend grab my tickets through the normal sale on Ticketmaster, and I'm feeling pretty lucky to have 'em.
That said, Craigslist seems to have a median of about $60-$70 for lawn tickets, which isn't too unreasonable -- I paid $45 after service charges.